In hindsight, your roommate's family should have been at the very least consulted first before making the decision to "drag" him into the mental hospital.
I also wonder what role his univerisity, his faculty and his professor has each played regarding his medical condition. Prima facie, they all owed him a duty of care, more than that of his friends, roommate and landlord, but I can't see any of that in your story, perhaps they all sat on their hands and did nothing.